I have a premium Spotify account with a few playlists. My OH has Spotify as well, but up until today, was able to access my playlist so that he can play music through his phone if I'm not in. He's just looked at his Spotify app and all the playlists that he could previously see, are missing.
I think you may need to log in to Spotify and either recover or restore playlists on you account if they are not there and then check that the collaborative option is tagged.
Thanks Togo, I've done all that.
It's a bit weird, we listen to Spotify through our Sonos speakers. When OH opens Spotify on his phone, there's no playlists, but if he opens the Sonos app, and opts for Spotify, the playlists come up.